Peat moss washing method and apparatus



July 14, 1964 R. w. KRONLUND 3,140,961

FEAT MOSS WASHING METHOD AND APPARATUS Filed April 12 1963 M J Paymon d W Kr'orzlund INVENTOR.

y Jay WJ? United States Patent 3,140,961 PEAT MOSS WASHING METHOD AND APPARATUS Raymond W. Kronlund, 7701 S. 46th Court W., Tacoma, Wash. Filed Apr. 12, 1963, Ser. No. 272,673 3 Claims. (Cl. 134-45) This invention relates to method and apparatus for washing crude peat moss in order to free it from finely divided impurities which, if present, would interfere with the normal commercial applications of the moss.

The method and apparatus of the present invention are applicable to the raw products obtained by excavating Sphagnum, or vertically growing moss peat bogs, and also hypnum, or horizontally growing peat moss bogs. These peat mosses are found in extensive deposits which are classed as primary deposits if relatively free from impurities, or secondary deposits if extensively contaminated with finely divided impurities such as marl, peat, slime, pumicite, clay, sand and wood fibers.

The secondary peat moss deposits obviously are many times more extensive than are the primary deposits and would afford a valuable and readily available source of peat moss if means were to be provided for separating the moss from the impurities.

It is impossible to effectuate such a separation during the digging operation. The concentrations or lenses of the impurities are irregularly distributed and occur at all depths so that it is impossible to dig around them, even with a mobile crane such as customarily is employed. Operation of the crane inevitably excavates some of the impurities and in addition inevitably disturbs the nonexcavated impurities, distributing them throughout the aqueous medium of the bog and further contaminating its peat moss content.

Accordingly it is the general object of the present invention to provide method and apparatus for separating efficiently finely divided impurities such as marl, slime, and clay from peat moss with which the impurities are intimately admixed, thereby improving the quality of the peat moss obtained while at the same time reducing its cost and making practical and profitable the commercial development of immense deposits of secondary peat moss which heretofore have not been useful commercially as a source of that product.

The manner in which the foregoing and other objects of the invention are accomplished will be apparent from the accompanying specification and claims considered together with the drawings, consisting of a view in side elevation of the herein described peat moss Washing apparatus.

Broadly stated, the presently described method of washing peat moss containing finely divided impurities comprises first depositing the peat moss on a porous blanket which advantageously may comprise a fibrous, porous blanket of wool, reinforced with synthetic fibers. Water is sprayed on the peat moss as it lies on the blanket, thereby dislodging the finely divided impurities. The sprayed peat moss then is pressed against the blanket, whereupon the spray Water and native water pass the impurities into and through the blanket while retaining i the washed peat moss on the blanket surface.

' The apparatus whereby the foregoing general procedure may be accomplished is contemplated for inclusion particularly in an apparatus sequence, the first unit of which is a peat moss disintegrator or macerator having for its function breaking up and flufling the packed moss as it is obtained from the bog. The disintegrated moss then is passed to the herein described washer where it is freed from finely divided impurities. It next is passed to a dehydrator of the class described in Kronlund, US.

2,694,360, after which it may be passed to a dehydrator and compounder wherein it may be dehydrated and processed for the inclusion of fertilizers, insecticides, soil conditioners and other additives.

The washing unit, described herein, broadly comprises a porous blanket which preferably is a driven, continuous blanket having stretches or segments on which the peat moss is subjected to the several stages of the processing operation.

Adjacent an infeed stretch are positioned means for delivering the raw peat moss to the blanket in a uniform stream at the desired rate. Opposite a washing stretch are positioned spray heads for spraying jets of water against the peat moss, freeing it of the finely divided impurities, and driving them into the blanket.

Working on a filtering stretch of the blanket are filter press means which remove a large proportion of the water from the blanket, driving it through the blanket. As the water is driven out in this manner, it takes with it a large proportion of the finely divided impurities.

Also associated with the blanket are doctor blades, or like means for scraping the cleaned peat moss from the blanket surface in the discharge stretch of the blanket, and blanket cleaning means for removing contained peat moss impurities associated with the cleaning stretch of the blanket.

Considering the foregoing in greater detail and with particular reference to the drawings:

The washing and dehydrating functions of the presently described apparatus may be accomplished in a single or plurality of stages, depending principally upon the identity and properties of the raw peat moss to be processed as well as upon the requirements to be met by the cleaned peat moss product. In the illustrated form of the invention the apparatus is so constructed as to provide two processing stages.

Accordingly the apparatus is mounted on infeed, central, and discharge frame units 10, 12, 14, respectively. These are interconnected by removable and interchangeable spacing bars 16, 18 and 20, 22 respectively. In this manner the spacing of the frame may be adjusted from time to time as required to accommodate or stretch a new blanket.

The raw peat moss is fed to the apparatus on a conveyor 24 which may communicate with the macerator as mentioned previously. The peat moss is discharged from the conveyor into a downwardly inclined chute 26 provided with a bonnet or hood 27. The conveyor is an integralpart of a picker roll unit 28. This unit serves a primary or ancillary disintegrating and fluffing function, as the case may be.

It consists of an upper, rotatably mounted, toothed roll 30 cooperating with a lower, rotatably mounted toothed r011 32. The two rolls are driven from a motor 34 coupled to a gear box 36 which drives a sprocket 38.

Sprocket 38 is connected by chain 40 to sprocket 42 on the shaft of picker roll 32. This roll in turn drives chain 44 connected to sprocket 46 on picker roll 30. Sprockets 42 and 46 are of different sizes. Accordingly the two rolls are driven at differential rates, as required to tear apart and separate the peat moss which they process.

The peat moss is discharged from chute 26 onto a long, continuous blanket 50 which is the key component of the present apparatus. It has for its function absorbing and transmitting the finely divided marl, slime and other impurities which it is desired to remove.

The blanket is supplied in a width determined in part by the capacity of the apparatus. It is made from a porous, flexible material preferably from a porous, fibrous textile product. Because of its strength and absorbent capacity, a wool blanket reinforced with nylon or other synthetic fiber is Well suited for the present purpose. Such a blanket is tough but stretchable so that it is not easily torn by sticks and stones which may be present in the peat moss. In addition, if it is damaged, it readily can be repaired in position on the machine.

Although the thickness and porosity of the blanket are somewhat variable, a nylon-reinforced, wool blanket which is about inch thick and has mesh openings of from inch in diameter, may be used to advantage.

Blanket 50 is supported in part on idler rolls 52, 54, 5, 58. It is further supported and driven by two pairs of filter press rolls to be described hereinafter. Although the arrangement on these rolls may be varied to suit different applications, in general it is preferred to have the infeed stretches of the blanket arranged with an upward inclination in order to achieve most effective washing.

After the disintegrated, raw peat moss has been deposited by bonneted chute 26 on the infeed stretch of belt 50, it is subjected to the action of spaced water jets supplied by pipe 60. The latter extends substantially the full length of the infeed stretch of the belt, parallel to it. Its jets spray the peat moss with sufficient force to dislodge the clay, marl, peat slime, wood fibers and other impurities which it is desired to remove. These are driven against and into the blanket where they subsequently may be removed.

A collecting trough 62 including a lower collecting segment and an exhausting duct 64 underlies the infeed stretch of the blanket. This collects water and impurities dislodged by the jets, and removes them through duct 64.

As the washed peat moss progresses on the blanket, it is levelled by means of a levelling bar 66, mounted on arms 68. The latter are fastened to frame 12, adjustably by means of bolts '70, so that the elevation of the working edge of the blade may be varied, thereby determining the thickness of the peat moss mat.

In the next phase of the operation the blanket with its burden of washed and water-saturated peat moss passes through a first filter press unit indicated generally at 72. This unit comprises a pair of cooperating rolls, one of which has a solid, pressure surface and the other of which is hollow and has a porous, filtering surface.

In the illustrated form of the invention the pressure roll comprises roll 74 mounted on a shaft 76, the ends of which are journaled in bearings 78. The bearings are supported on a pair of arms 8t), one end of which is pivoted to frame 12 by means of pins 82.

Resilient pressure is supplied to the rolls by passing rods 84 through the other end of arms 89. The upper ends of the rods are threaded and mount adjusting nuts 26. Washers 88 are retained by the nuts and compression springs 90 are interposed between the washers and the ends of arms 80. In this manner the upper roll 72 is maintained under adjustable and resilient pressure at all times. Furthermore, the arrangement is such that the roll can give easily if a large rock or stick inadvertently is passed beneath it.

The surface of roll 74 is hard and durable and may be provided, for example, by an outer layer of hard rubber.

Cooperating with roll 74 is a second roll 92 about which blanket 50 is reeved. The shafts of roll 92 are journaled in bearings M mounted on the frame unit 12.

Roll 92 is hollow and its outer surface is perforated. The surface covering may comprise, for example, hot rolled steel screen having openings over approximately 40% of its peripheral area.

A collecting trough 96 with exhaust duct 98 is located below perforated roll 92 to remove Water and sediment separated by the roll from the peat moss.

After passing over the filter press stretch of belt 50, provided by rolls 74, 92, the Washed and partly dehydrated peat moss passes to a discharge stretch. This segment is angled inwardly so that the peat moss tends to drop off by gravity. In addition, there may be supplied a doctor blade 100 mounted on arms 102 which are bolted adjust- 4 ably to frame 12. Suitable adjustment thus can be made as required to scrape any residual peat moss from the surface of the belt.

If a single stage washing operation is contemplated, the belt next may be cleaned and then cycled to the infeed section of the unit. However, in the illustrated form of the invention a two stage operation is employed for particularly efficient washing and cleaning of the peat moss.

Hence pulley 54 is so arranged as to provide a second, upwardly inclined, feeding stretch of the belt upon which the partially cleaned peat moss tumbles. Along this stretch there is provided a second pipe 1&6 which discharges Water at high pressure through a plurality of spaced jets. The water jets again saturate the peat moss and wash residual sediment from it. The washings pass through the belt and are collected in a collecting trough N8 provided with an exhaust duct 110.

The saturated and washed peat moss then passes through a second filter press unit, indicated generally at 112. This unit corresponds in structure and function to unit '72. It is comprised of a pressure roll 114 and a cooperating, perforated, filter roll 116 between which belt 5% and its burden of peat moss passes. Water passing into and through roll 116 drains into a trough 118 and out through duct 12%.

After the peat moss passes between rolls 114, 116, it is discharged gravitationally into a discharge chute 122, an adjustable doctor blade 124 being positioned for scraping residual peat moss from the surface of the belt. The peat moss then may be passed, as explained above, to a dehydrating unit for complete removal of its water, after which it is baled and sold.

Belt 55) continues in its travel about idler pulleys S6, 58 to a cleaning section. Here it is beaten and at the same time washed with high pressure jets of Water. The beating means comprise one or more blade-equipped beater rolls 126 rotatably mounted beneath the belt and the washing means comprises high pressure water jet spray units 128. The dislodged material and surplus Water are drained into pans 13d whence they are exhausted through ducts 132.

Blanket 515 and filter press units 72, 112 may be driven from a common motor 134. Sprocket 136 on the motor drives a first chain 138 which engages sprockets 140, 142 on the shafts of rolls 74, 114, respectively, driving the rolls in the same direction of rotation and at the same speed.

Sprocket 136 also drives a chain 144 which engages sprocket 146, 143 on the shafts of rolls 92, 116, respectively, driving them also in the same direction and at the same rate of speed. A chain take-off 150 from the shaft of roll 74 drives beater roll 26. A second chain takeoff 152 from the shaft of roll 92 drives beater roll 104. Thus all of the units of the apparatus may be driven synchronously at the desired speed.

Operation The operation of the herein described peat moss washing apparatus is as follows:

Raw peat moss from conveyor 24 is discharged into chute 26, where it is disintegrated and fluffed by picker roll unit 28.

The disintegrated peat moss then passes to porous blanket 50 where it is sprayed by high pressure jets 60. The peat moss layer on the blanket is adjusted as to depth by doctor blades 66, after which it is passed through a filter press unit 72. This removes the water together with a large amount of the contaminating marl, pumice, slime, etc.

Next, the peat moss is scraped off the blanket by doctor blade 100, after which it drops again on blanket 50 and is sprayed by high pressure jets 106. These again saturate the moss and dislodge a further quantity of sediment. The saturated moss then is passed through a second filter press unit 112 which accomplishes further cleaning. Doctor blade 124 acts to scrape the cleaned moss from the blanket and to transfer it to discharge chute 122 for further processing. In this manner even secondary grade peat moss may be cleaned rapidly, effectively, and economically, and made suitable for use in the various applications to which peat moss customarily is applied.

It is to be understood that the form of my invention herein shown and described is to be taken as a preferred example of the same and that various changes in the shape, size and arrangement of parts may be resorted to without departing from the spirit of my invention or the scope of the subjoined claims.

Having thus described my invention, I claim:

1. The method of Washing peat moss containing slime, marl, pumicite and other finely divided impurities which method comprises:

(a) depositing the peat moss in particulate form loosely on a moving, continuous, porous blanket, water absorbent,

(b) spraying the peat moss as it lies on the blanket with jets of Water with sufficient force to dislodge the impurities from the peat moss,

(c) passing the washed peat moss and supporting blanket between a pair of press rolls with one roll engaging the peat moss and the other roll engaging the blanket for pressing the water and impurities into and through the blanket while retaining the l washed peat moss on the blanket surface,

7 (d) removing the washed peat moss from the blanket,

l (e) and removing the extracted peat moss impurities from the blanket.

2. Apparatus for washing peat moss containing slime, marl, pumicite and other finely divided impurities which apparatus comprises:

(a) a continuously driven porous, water absorbent blanket arranged with successively following infeed washing, filtering, discharging and cleaning stretches,

(b) feed means for feeding the raw peat moss in particulate form loosely to the infeed stretch of the blanket,

(0) water spray means for spraying the peat moss on the washing stretch of the blanket with jets of water with sufiicient force to dislodge the impurities from the peat moss,

(d) a pair of filter press rolls working on the filter stretch of the blanket with one roll engaging the washed peat moss and the other roll engaging the blanket for pressing the water and impurities into and through the blanket while retaining the washed peat moss on the blanket surface,

(e) peat moss discharging means for separating the washed and pressed peat moss from the discharge stretch of the blanket, and

(f) blanket cleaning means positioned for removing the impurities from the cleaning stretch of the blanket.

3. The apparatus of claim 2 wherein the press filter roll engaging the peat moss is provided with a pressure contact surface and the roll engaging the blanket is hollow and has a perforated peripheral surface.

References Cited in the file of this patent UNITED STATES PATENTS 899,339 Shuman Sept. 22, 1908 1,239,066 Winters Sept. 4, 1917 1,527,369 Meyer Feb. 24, 1925 1,793,246 Phillips Feb. 17, 1931 2,423,828 Chagnon July 15, 1947 2,506,372 MacDonald May 2, 1950 2,686,192 Bonotto Aug. 10, 1954 2,821,771 Skeer Feb. 4, 1958 2,907,388 Seaman Oct. 6, 1959 FOREIGN PATENTS 715,800 Germany Jan. 7, 1942 

1. THE METHOD OF WASHING PEAT MOSS CONTAINING SLIME, MARL, PUMICITE AND OTHER FINELY DIVIDED IMPURITIES WHICH METHOD COMPRISES: (A) DEPOSITING THE PEAT MOSS IN PARTICULATE FORM LOOSELY ON A MOVING, CONTINUOUS, POROUS BLANKET, WATER ABSORBENT, (B) SPRAYING THE PEAT MOSS AS IT LIES ON THE BLANKET WITH JETS OF WATER WITH SUFFICIENT FORCE TO DISLODGE THE IMPURITIES FROM THE PEAT MOSS (C) PASSING THE WASHED PEAT MOSS AND SUPPORTING BLANKET BETWEEN A PAIR OF PRESS ROLLS WITH ONE ROLL ENGAGING THE PEAT MOSS AND THE OTHER ROLL ENGAGING THE BLANKET FOR PRESSING THE WATER AND IMPURITIES INTO AND THROUGH THE BLANKET WHILE RETAINING THE WASHED PEAT MOSS ON THE BLANKET SURFACE. 